1. Field of the Invention
This invention relates, generally, to bailers. More particularly, it relates to a bailer that is bottom-emptied to avoid contamination by oxygen.
2. Description of the Prior Art
U.S. pending patent application Ser. No. 10/707,291 discloses ball valve positioned within a tapered check valve seat positioned at the leading end of a bailer. When the ball valve is fully seated within the valve seat formed on an interior surface of the valve housing, liquid fluid within the hollow interior of the bailer is sealed within said hollow interior. When the ball valve is unseated from the valve seat, liquid fluid within the hollow interior of the bailer flows past the unseated ball valve and into a container positioned below the check valve seat to collect the liquid fluid.
Bailers are best emptied from the bottom because unacceptable amounts of oxygen are introduced into the sample if the bailer is decanted from the top.
The ball valve of the co-pending patent application depends at least to some extent from the bottom of the bailer. Accordingly, placing the bailer on a flat surface drives the ball valve upwardly into the valve housing so that the liquid fluid content of the bailer begins flowing out.
However, oxygen is introduced into the liquid fluid as it flows out of the bailer into a capturing device because the valve seat upon which the ball valve sits is spaced sufficiently far from the bottom of the check valve housing to form an annular air pocket around the ball valve. The oxygen in the air mixes with the liquid fluid content of the bailer during the emptying process, producing a false reading of the oxygen content of the liquid fluid.
An improved ball valve is therefore needed. The improved ball valve would substantially eliminate all oxygen contact with the liquid fluid as said liquid fluid is emptied from the bottom of the check valve.
However, in view of the prior art considered as a whole at the time the present invention was made, it was not obvious to those of ordinary skill in the pertinent art how the art could be advanced to provide a bottom-emptying bailer having a ball valve that eliminates oxygen entry into the liquid at the time of bailer decanting.